The ex-Clinchfield, now CSX, begins its assault on the Blue Ridge escarpment with a horseshoe curve at Ashford, NC. Google Earth follows the route as it uses u-turns and multiple tunnels to reach the summit at Altapass, along the Blue Ridge Parkway. I highlighted the tracks with a red line to show how the route is laid out. It would be neat if Google Earth could go through the tunnels instead of over them, but I don't think that'll happen anytime soon. By the way, be sure to watch in high quality because standard quality looks badly out of focus.